Method of fabricating a layered material



Jan. 11, 1966 c. .1. SEBY METHOD OF FABRICATING A LAYERED MATERIAL Filed Dec. 12, 1962 E E H 5 T E M T H m L R rt W 0 L 3 i fiw ms 8 Ma @m 0 A M m9 3,228,818 METHOD OF FABRICATING A LAYERED MATERIAL Carl Joel Seby, Fenixvagen 16, Enebyberg, Sweden Filed Dec. 12, 1962, Ser. No. 244,156 Claims priority, application Sweden, Aug. 10, 1962, 8,761/ 62 7 Claims. (Cl. 156-92) The instant invention refers to a method of fabricating layered materials with at least one outside surface comprising a light metal sheet which is glued to a base of veneer, a compressed laminated product of wood, plywood, particle board or wallboard. Layered materials made up of a sheet of light metal glued to a plywood plate are known in the art. They are characterized by comparatively great bending and breaking strength and are comparatively insensitive to impact.

The object of the instant invention is to further improve layered materials of this type. For one thing the invention makes use of a sheet of light metal which at least on the side that is to face the plate of veneer etc. is provided with small waves, is granulated or is patterned in some other way. For another thing, after both the wavy or granulated light metal surface and the surface of the veneer, etc., which will face said light metal surface when the light metal and veneer etc. are glued together, have been provided with glue or other substance necessary for said gluing, the two adjoining surfaces are subjected to pressure forcing them against each other, said pressure being so great that the wavyness, granularity etc. of said light metal sheet penetrates into the surface of veneer, etc., and develops a permanent deformation of material in the latter. Said pressure should preferably be greater than about 213 pounds per square inch (15 kg./cm. and it should be retained until the glue joint has hardened.

According to an embodiment of the invention light metal sheets of this type are applied to each side of a plate of veneer, etc., said sheets of light metal preferably being patterned or granualted on both sides.

For gluing it would be preferable to use a glue of phenol, resorcinol or carbamide type, said glue being applied to the surface of the wallboard or plywood etc., whereas the metal surface after being degreased and somewhat roughened, for instance by pickling with a solution of caustic soda or by sand blasting, is provided with a coating of an appropriate composition of casein latex. If desired, the sheet thus pretreated can be coated with the same type of glue as the surface of the wallboard etc. after said composition has dried.

Instead of glue of the above-mentioned type it would also be possible to use a contact glue made on the basis of natural rubber or on the basis of synthetic rubber, for instance neoprene. In this case both the joining surfaces would be coated with the contact glue in question after cleaning and finishing or sandblasting, respectively.

Finally, also a glue of epoxy resin type could be used, which in certain cases will give a very strong joint.

The accompanying drawing shows an embodiment of the layered material according to the invention. Particularly, FIGURE 1 shows a large portion of a sheet or base plate 1 of veneer, which on both sides has been provided with coatings 2 and 3 in the form of sheets of perforate, granulated light metal. FIG. 1 is to illustrate the utilization of a glue of contact type. The lower light metal sheet 3 is already attached to the bottom side of the veneer 1, whereas a corner 4 of the upper light metal sheet 2 has not yet been pressed against the underlying veneer.

FIG. 2 shows a portion of the layered material of FIG. 1 after the metal sheets and veneer have been pressed together. It will be seen that the waves or the granulaite States Patent tions on the insides of the light metal sheets 2, 3 have provided a permanent deformation in the wallboard 1 as a result of the pressure.

By means of the method of the invention there is provided a layered material, which contrary to what anyone skilled in the art of gluing would expect actually sticks together in the glue joints and which in reality has greater adhesive force in the joint for the same plate size than known layered materials because the active joint surface has been enlarged by the deformation of the fiber material and which moreover thanks to the wavy or granulated joint surface gives the layered material of the invention greater strength against breaking and bending than known layered materials.

In the following a few examples of the method according to the invention and of the layered material obtained by said method will be disclosed.

Example 1 A layer of birch plywood is cleaned and smoothed and is coated on both sides with a glue of phenol type. The glue can be spread out manually either by means of a spatula or a brush or by spreading rollers. The two plywood surfaces pretreated in this manner are then to be provided with light metal sheets granulated on both sides, so called embossed stucco sheeting.

The two surfaces of the light metal sheets facing the plywood are treated in the following manner: They are first cleaned from grease, for instance by means of a weak alkaline solution, and may thereafter be sand blasted if desired, if the pickling provided by said solution is not satisfactory for the adhesion. The surfaces pretreated in this manner are then coated with an appropriate composition of casein latex, for instance by means of a brush. After this composition has dried and resulted in a layer adhering with great strength to the sheet surfaces the light metal surfaces which have been pretreated in the manner disclosed above are pressed against the glued surfaces of the plywood after these have dried to sticky condition. Alternatively said layer of casein latex can be provided with a layer of phenol glue before the joint surfaces are brought together. After the glue surfaces thus have been completed the light metal sheets and the plate of veneer are pressed together in a press having so high pressure that the granularities in the two light metal sheets result in a permanent deformation in the two faces of the plywood, said deformation not only increasing the adhering area in the joint but also giving exceptionally good qualities of strength to the completed layered plate. The pressure is adjusted with respect to the hardness of the birch plywood. The preferable pressure for birch plywood of average quality would be about 286 pounds per square inch (20 kg./cm. A slightly lower pressure could be used for pine plywood. About 213 pounds per square inch (15 kg./cm. would be satisfactory in this case.

An appropriate granularity of the light metal sheet would be about 4-20 mils (0.1-0.5 mm.) depending on the thickness of the layered plates which are to be fabricated and on the deformation which can be permitted in the intermediate layer. Of course, the metal sheet must be sufficienlty dense, strong or thick so that the granulations formed on at least one surface remain as granulations while the sheet and base plate are pressed together, the granulations passing into the surface of the less dense base plate and causing a deformation of the latter.

Example 2 A particle board plate is cleaned and smoothed on one side and coated with a glue of neoprene type. Coating can be effected by means of a spatula or the particle board plate can be passed under a spreading roller. A granulated surface sheet metal plate is to be made to adhere to the particle board plate surface treated in this manner. The sheet metal plate is cleaned on its surface facing the particle board plate by an appropriate degreasing agent, for instance carbon tetrachloride, trichloroethylene or a 5 percent solution of caustic soda. In this case the work must be effected under appropriate airing conditions. After degreasing the metal surface is roughened slightly, for instance by sandblasting, and said surface is then coated with a glue of neoprene type. After the glue applied to both the particle board plate and the metal plate has dried so much that the surface does not stick to ones fingers the two surfaces are brought together, care being taken that said two surfaces are centered to the required extent with respect to each other. After the two glued surfaces thus have been brought together the layered plate is subjected to so great a pressure, that the granularities of the light metal sheet are pressed into the particles of the particle board plate thus deforming the surface of the particle board plate. An appropriate pressure would also in this case be between about 213 and 286 pounds per square inch (20 kg./cm.

Although the invention has been described in connection with embodiments of the same it is not restricted to these and it can be modified in an arbitrary manner within the scope of the following claims, which besides the method also are intended to protect the layered material fabricated in accordance with said method.

What I claim is:

1. A method of fabricating a double layer material composed of an imperforate metal sheet, having at least one granulated surface, and a base plate formed from a less dense non-metallic material, the steps comprising applying adhesive to the granulated surface of the sheet and to the surface of the base plate which will be in contact with the metal sheet, and

pressing the adhesively coated surfaces of the sheet and base plate together with sufiicient force so as to cause the granulations on the surface of the metal sheet to penetrate through the adhesive and into the surface of the base plate, developing in the latter a permanent deformation of material.

2. The method of fabricating a double layer material as defined in claim 1 wherein the granulations protrude beyond the normal surface of the sheet a distance between approximately 0.1 and 0.5 mm.

3. The method of fabricating a double layer material 4 as defined in claim 1 wherein the base plate is composed of veneer or plywood.

4. A method of fabricating a multi-layer material having both outside surfaces composed of an imperforate metallic sheet, each sheet having at least one granulated surface, and a base plate located therebetween formed from a less dense non-metallic material, the steps comprising applying adhesive to both surfaces of the base plate and to the granulated surfaces of the two metallic sheets which will be in contact with the base plate,

bringing the adhesively coated granulated surfaces of the two metallic sheets into contact with the surfaces of the base plate, and

pressing the two metallic sheets toward one another,

said pressure being sufiicient to cause the granulations on the surface of each metallic sheet to penetrate through the adhesive and into the surfaces of the base plate, developing in the latter a permanent deformation of material.

5. The method of fabricating a multi-layer material as defined in claim 4 wherein the base plate is composed of veneer or plywood.

6. The method of fabricating a multi-layer material as defined in claim 4 further including the step of cleaning and roughening the granulated surfaces of the metallic sheets which will contact the base plate before applying adhesive to said surfaces thereby enhancing the binding between the adhesive and metallic sheets.

7. The method of fabricating a multi-layer material as defined in claim 4 wherein the granulations protrude beyond the normal surface of the sheets a distance between approximately 0.1 and 0.5 mm.

References Cited by the Examiner UNITED STATES PATENTS 1,810,281 6/1931 Linse 156153 2,252,555 8/1941 Carothers 161230 2,376,854 5/1945 Saunders et al. 161'217 2,609,352 9/1952 Kv alnes 156-335 2,647,852 8/1953 Franklin 156261 2,699,417 1/1955 Repsher 156335 FOREIGN PATENTS 539,328 4/1957 Canada. 589,260 6/ 1947' Great Britain.

EARL M. BERGERT, Primary Examiner. 

1. A METHOD OF FABRICATING A DOUBLE LAYER MATERIAL COMPOSED OF AN IMPERFORATE METAL SHEET, HAVING AT LEAST ONE GRANULATED SURFACE, AND A BASE PLATE FORMED FROM A LESS DENSE NON-METALLIC MATERIAL, THE STEPS COMPRISING APPLYING ADHESIVE TO THE GRANULATED SURFACE OF THE SHEET AND TO THE SURFACE OF THE BASE PLATE WHICH WILL BE IN CONTACT WITH THE METAL SHEET, AND PRESSING THE ADHESIVELY COATED SURFACES OF THE SHEET AND BASE PLATE TOGETHER WITH SUFFICIENT FORCE SO AS TO CAUSE THE GRANULATIONS ON THE SURFACE OF THE METAL SHEET TO PENETRATE THROUGH THE ADHESIVE AND INTO THE SURFACE OF THE BASE PLATE, DEVELOPING IN THE LATTER A PERMANENT DEFORMATION OF MATERIAL. 